Biological attributes of age-0 lake sturgeon in the lower Peshtigo River, Wisconsin

Lake sturgeon Acipenser fulvescens are imperiled throughout the Laurentian Great Lakes basin. Efforts to restore this species to former population levels have been ineffective due in part to limited information regarding its early life history. The objectives of this study were to characterize the larval drift and biological attributes of age‐0 lake sturgeon in the lower Peshtigo River, Wisconsin. Lake sturgeon larvae were captured from May to June 2002 and 2003 using drift nets, while age‐0 juveniles were captured from June through October 2002 and 2003 using wading, snorkeling, backpack electrofishing, and haul‐seine surveys. Larval drift occurred within 14 days of adult spawning and extended from 1 to 3 weeks in duration, with two peaks in the number of fish drifting downstream each year. Larvae had a median total length (TL) of 19 mm (range: 13–23; N = 159) in 2002 and 18 mm (range: 13–24; N = 652) in 2003. Catch‐per‐unit‐effort for larvae was 0.18 fish h^?1 m² and 0.94 fish h^?1 m² in 2002 and 2003, respectively. Age‐0 juvenile lake sturgeon exhibited rapid growth (i.e. 2.57 mm day^?1 in TL and 0.66 g day^?1 in wet weight) throughout summer and fall months; relative condition of fish in both years was approximately 100, indicating good condition. Absolute abundance of age‐0 juveniles in 2003 was estimated at 261 fish using the Schnabel estimator. The results from this study indicate that the lower Peshtigo River contains important nursery habitats suitable for age‐0 lake sturgeon.     

Savanna in central Wisconsin,U.S.A.

Summary A black oak savanna in central Wisconsin was analyzed in detail, including canopy trees, understory and tree seedlings. Although many authors have held that savanna in this region is a subclimax maintained by fire, this stand, unburned for many years, shows a high degree of stability and very little trend toward the postulated increase in trees. Of the 25 most frequent understory species, 80% have higher affinity for prairie or other very open habitats than for forest. Although oak seedlings had 72% frequency in 1 m² quadrats, their growth is exceedingly slow, while dieback and mortality are very high; few survive to 1 m in height and saplings are nearly absent. The tree canopy at 40% is low in relation to B. A., probably due to frequent wind and lightning damage. The inhibition of oak seedlings which prevents succession toward forest appears to be caused by a combination of frost, drouth, sandy soil of low water retaining capacity, interspecific competition and allelopathy; seedlings in an adjacent old field grow approximately 3 times faster, with little injury or mortality. Light grazing in early years of settlement may have allowed a temporary increase in tree establishment, since over 2/3 of the present canopy trees appear to be in one age group of 105–110 years. On the basis of this evidence we propose that at least some savanna sites in this region are naturally stable communities maintained by a complex interaction of the local climate, edaphic factors, and the existing community; fire is not an essential factor.

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Résumé La Savane à Chêne noir du Wisconsin central est analysée en détail, comprenant arbres, arbustes et semis d'arbres. Beaucoup d'auteurs considèrent cette Savane d?e à l'incendie. Notre groupement pas soumis à l'incendie depuis beaucoup d'années montre un haut degré de stabilité. Des 25 espèces les plus fréquentes du sous-bois 80% montrent davantage d'affinité avec la prairie où d'autres stations ouvertes qu'avec la forêt. Sur une surface de 1 m² les semis deQuercus ont une fréquence de 72%. Ils poussent très lentement et la mortalité est très grande, la hauteur de la strate arbustive, influencée par les vents fréquents est faible. L'évolution très lente des semis de Chêne semble causée par une combinaison de froid, sêcheresse, sol sablonneux, d'une faible capacité de retenu d'eau, concurrence interspécifique. Dans un vieux champ, les semis poussent à peu près 3 fois plus vite et montrent une plus faible mortalité. Plus de 2/3 des individus de la strate arborescente ont 105–110 ans. Tenant compte de ces faits, nous pouvons admettre qu'au moins certaines Savanes de cette région sont des unités naturelles, stables, maintenues dans cet état par une interaction du climat local, des facteurs édaphiques et de la végétation existante. Le feu n'est pas un facteur essentiel.

     

Savanna in central Wisconsin,U.S.A.

Summary A black oak savanna in central Wisconsin was analyzed in detail, including canopy trees, understory and tree seedlings. Although many authors have held that savanna in this region is a subclimax maintained by fire, this stand, unburned for many years, shows a high degree of stability and very little trend toward the postulated increase in trees. Of the 25 most frequent understory species, 80 % have higher affinity for prairie or other very open habitats than for forest. Although oak seedlings had 72 % frequency in 1 m² quadrats, their growth is exceedingly slow, while dieback and mortality are very high; few survive to 1 m in height and saplings are nearly absent. The tree canopy at 40 % is low in relation to B. A., probably due to frequent wind and lightning damage. The inhibition of oak seedlings which prevents succession toward forest appears to be caused by a combination of frost, drouth, sandy soil of low water retaining capacity, interspecific competition and allelopathy; seedlings in an adjacent old field grow approximately 3 times faster, with little injury or mortality. Light grazing in early years of settlement may have allowed a temporary increase in tree establishment, since over 2/3 of the present canopy trees appear to be in one age group of 105–110 years. On the basis of this evidence we propose that at least some savanna sites in this region are naturally stable communities maintained by a complex interaction of the local climate, edaphic factors, and the existing community; fire is not an essential factor.

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Résumé La Savane à Chêne noir du Wisconsin central est analysée en détail, comprenant arbres, arbustes et semis d'arbres. Beaucoup d'auteurs considèrent cette Savane d?e à l'incendie. Notre groupement pas soumis à l'incendie depuis beaucoup d'années montre un haut degré de stabilité. Des 25 espèces les plus fréquentes du sous-bois 80 % montrent davantage d'affinité avec la prairie où d'autres stations ouvertes qu'avec la forêt. Sur une surface de 1 m² les semis deQuercus ont une fréquence de 72 %. Ils poussent très lentement et la mortalité est très grande, la hauteur de la strate arbustive, influencée par les vents fréquents est faible. L'évolution très lente des semis de Chêne semble causée par une combinaison de froid, sêcheresse, sol sablonneux, d'une faible capacité de retenu d'eau, concurrence interspécifique. Dans un vieux champ, les semis poussent à peu près 3 fois plus vite et montrent une plus faible mortalité. Plus de 2/3 des individus de la strate arborescente ont 105–110 ans. Tenant compte de ces faits, nous pouvons admettre qu'au moins certaines Savanes de cette région sont des unités naturelles, stables, maintenues dans cet état par une interaction du climat local, des facteurs édaphiques et de la végétation existante. Le feu n'est pas un facteur essentiel.

     

Wisconsin Twin Panel.

The Wisconsin Twin Panel was initiated in 1994 to serve a study of the development of childhood mood and behavioral disorders. Families who give birth to twins within the state of Wisconsin are recruited within 6 months of the birth. The panel currently supports three ongoing, longitudinal research projects. Research foci include studying epigenetic contributions to emotional, physical, cognitive, and motoric development of infant and toddler twins; physiological concomitants of childhood temperament; and early risk and resiliency factors related to child psychopathology. All three studies include videotaped observational assessments and biological measures.     

Abundance and movement patterns of age-0 juvenile lake sturgeon in the Peshtigo River,Wisconsin

In Great Lakes tributaries, age-0 juvenile lake sturgeon Acipenser fulvescens use riverine nursery habitats during their first summer of life and migrate to adjacent lakes after a seasonal decline in water temperature. We used mark-recapture data collected during this river-residency phase to monitor patterns in juvenile abundance and movement in the Peshtigo River, Wisconsin, during 2006 and 2007. Jolly-Seber and multistate models were used to estimate abundance and describe the probability of movement between river sections. Juvenile abundance was higher in 2007 than in 2006; however, in both years, abundance at the end of the sampling season was lower than at the beginning. Downstream movements were observed more frequently than upstream movements, and the probability of a downstream movement was higher than the probability of an upstream movement. The lower abundance later in the sampling season and propensity for downstream movements suggests that some age-0 juvenile lake sturgeon may leave the natal river before a seasonal decline in water temperature.     

Pluteus aurantipes sp. nov. from Wisconsin, United States

Pluteus aurantipes sp. nov. was discovered in Wisconsin, United States. This agaric species is characterized by its yellowish brown pileus, reddish orange stipe, pileipellis consisting of a trichoderm and lack of pleurocystidia.     

Development of molecular biology at the University of Wisconsin, Madison.

Dramatic changes in the foundation of academic departments in our universities are uncommon. With the demonstration that DNA was the cellular source of genetic information, and that this information could be regulated, the field of molecular biology was born. Later, when scientists found that they could tinker with this information, the field matured. In an unusually rapid manner, molecular biology was integrated into the University of Wisconsin, Madison, in the late 1950s and early 1960s. This present article is a chronology of how it happened. What are the factors that made this transition possible in the University of Wisconsin? What lessons have we learned from this experience?     

Lyme disease in Wisconsin: epidemiologic, clinical, serologic, and entomologic findings

In 1980-82, 80 individuals (71 Wisconsin residents) had confirmed Lyme disease (LD-c) reported; 39 additional patients had probable or possible LD. All cases of LD-c occurred during May-November; 73 percent occurred during June-July; 54 (68 percent) occurred in males. The mean age was 38.7 years (range, 7-77 years). Among LD-c patients, likely exposure to the presumed vector Ixodes dammini (ID) occurred in 22 different Wisconsin counties. Antibodies to the ID spirochete that causes LD occurred in 33 of 49 LD-c cases versus 0 of 18 in ill controls (p less than .001) and in 13 of 26 LD-c cases treated with penicillin or tetracycline versus 16 of 19 LD-c cases not treated. Early antibiotic therapy appears to blunt the antibody response to the ID spirochete. Regional tick surveys conducted in Wisconsin during each November in 1979-82 have demonstrated regions of greater density of ID. Utilizing comparable tick collection in these surveys, increases were noted in the percentage of deer with ID from 24 percent (31/128) in 1979 to 38 percent (58/152) in 1981, in the standardized mean value of ID/deer from 1.0 in 1979 to 2.2 in 1981, in the percentage of ID of the total ticks collected from 13 percent in 1979 to 71 percent in 1981, or in the ratio of ID to Dermacentor albipictus ticks from 0.14 in 1979 to 2.44 in 1981. However, a reduction in the density of ID/deer was noted generally throughout Wisconsin in 1982 when compared to 1981. LD is widespread in Wisconsin, with ecologic and clinical features similar to those occurring along the eastern seaboard.     

Meeting report: 2010 Caenorhabditis elegans Neurobiology Meeting, University of Wisconsin, USA

Against the backdrop of the scenic Lake Mendota, the C. elegans Neurobiology Meeting came to a head. Expertly organised by Brian Ackley and Bruce Bamber and hosted at the accommodating University of Wisconsin, the meeting brought together recent contributions from many of the major research groups working on the neurobiology of C. elegans. With seven keynote speakers, 57 verbal presentations and hundreds of posters, this exciting event spanned a fascinating 3 days from 27 June to 30 June 2010. In keeping with the tradition of this conference, the event on the whole was spearheaded by young investigators from several research institutions. The meeting served to emphasise the gains enjoyed by taking advantage of the genetic tractability of the worm. A thread that ran through the meeting was the importance of integrating data across different levels of biological organisation to permit delineation of the physiology underpinning discrete behavioural states. Recent advances in optogenetics and microfluidics were at the forefront of refining these analyses. The presentations discussed in this meeting report are a selection which reflects this overarching theme.